The 10 Most Latter-Day Saint Counties
Identifying the most LDS counties and how they voted in the past 5 elections
Introduction
Note: I retroactively updated a few things after I realized that there were two counties that had a higher church record number than population, previously I capped those two counties at 99% not thinking about this scenario.
I recently came across the US Religion Census where membership is estimated at the county level for 250+ religions. When I looked through their methodology, they claim they contact each religion and ask for their membership record numbers by county. They had the numbers for the Church of Jesus Christ of Latter-day Saints and when I summed them up it estimated 6.5 million members in the US for 2020. This lines up well with the church statistics page’s official record count in the US.
Today, let’s find the counties with the highest LDS membership percentage compared to the total county population and how they voted in the last 5 elections.
Charts
Mormonism (including Latter-day Saints) is densely populated in the west. All of our top 10 counties are all found in Utah and Idaho - mostly in rural areas.
Interestingly, the most Latter-day Saint counties are clustered in the same area. So if you were looking for the MOST latter-day saint place in the country, just fly into salt lake and drive up to the south eastern tip of Idaho. 90% or more of the people in this area are on church records - the most Latter-day Saint county actually being in Idaho!
I discovered in two counties in the US there are more people on church records than the county population: Franklin, ID and Rich, UT. In 2020 Franklin ID, the county population was 14,215 according to the census, but the church records indicate 16,095.
Unsurprisingly, the most Latter-day Saint counties are rural with the exception of Utah county where 83% of the county population is on church records! Also, while Cache county isn’t particularly urban, it has a higher population than the others because of Utah State University and Logan, Utah
.When we look at voting patterns in places where 70+% of the population is on church records, we see that…
The Red vote was very strong in 2012 with Romney. 93% of voters in Franklin, Idaho voted for Romney.
In 2016, the red vote dipped significantly with large portions of the vote share going to Evan McMullin. He appeared on both the Utah and the Idaho ballot that year.
The 2024 vote year was similar to the 2008 vote year except in the most LDS rural counties more seemed to vote for Trump than McCain; however, in the more Urban LDS counties more overall have moved away from the Trump vs. McCain.
This could be an interesting insight and I’m thinking either 1 of 2 different things…
Rural LDS republicans haven’t moved anywhere in the last 20 years, its the urban LDS republicans. Though, we must keep in mind, some of the movement is probably due to more democratic immigration into the urban areas of Utah bringing the republican voting numbers down.
If the urban democratic vote shift in Utah is ALL simply due to democratic immigration, then maybe all of the articles about Latter-day Saints leaving the democratic party are not true. LDS GOP vote simply peaked with Romney (for obvious reasons) and is about the same now in 2024/25 as it was before Romney in 2008.
What do you think about this? Would love to hear others thoughts and theories.
Where is Madison County? I see it's on the map but not the list. I remember finding a dataset on the ARDA (https://www.thearda.com/) that has religious membership for each US county, scaled so it is out of 1000. The estimate for Madison county was slightly *over* 1000.